/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Copyright 2011, Blender Foundation.
 */

#include "COM_TonemapOperation.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"

extern "C" {
#include "IMB_colormanagement.h"
}

TonemapOperation::TonemapOperation() : NodeOperation()
{
  this->addInputSocket(COM_DT_COLOR, COM_SC_NO_RESIZE);
  this->addOutputSocket(COM_DT_COLOR);
  this->m_imageReader = NULL;
  this->m_data = NULL;
  this->m_cachedInstance = NULL;
  this->setComplex(true);
}
void TonemapOperation::initExecution()
{
  this->m_imageReader = this->getInputSocketReader(0);
  NodeOperation::initMutex();
}

void TonemapOperation::executePixel(float output[4], int x, int y, void *data)
{
  AvgLogLum *avg = (AvgLogLum *)data;

  this->m_imageReader->read(output, x, y, NULL);
  mul_v3_fl(output, avg->al);
  float dr = output[0] + this->m_data->offset;
  float dg = output[1] + this->m_data->offset;
  float db = output[2] + this->m_data->offset;
  output[0] /= ((dr == 0.0f) ? 1.0f : dr);
  output[1] /= ((dg == 0.0f) ? 1.0f : dg);
  output[2] /= ((db == 0.0f) ? 1.0f : db);
  const float igm = avg->igm;
  if (igm != 0.0f) {
    output[0] = powf(max(output[0], 0.0f), igm);
    output[1] = powf(max(output[1], 0.0f), igm);
    output[2] = powf(max(output[2], 0.0f), igm);
  }
}
void PhotoreceptorTonemapOperation::executePixel(float output[4], int x, int y, void *data)
{
  AvgLogLum *avg = (AvgLogLum *)data;
  NodeTonemap *ntm = this->m_data;

  const float f = expf(-this->m_data->f);
  const float m = (ntm->m > 0.0f) ? ntm->m : (0.3f + 0.7f * powf(avg->auto_key, 1.4f));
  const float ic = 1.0f - ntm->c, ia = 1.0f - ntm->a;

  this->m_imageReader->read(output, x, y, NULL);

  const float L = IMB_colormanagement_get_luminance(output);
  float I_l = output[0] + ic * (L - output[0]);
  float I_g = avg->cav[0] + ic * (avg->lav - avg->cav[0]);
  float I_a = I_l + ia * (I_g - I_l);
  output[0] /= (output[0] + powf(f * I_a, m));
  I_l = output[1] + ic * (L - output[1]);
  I_g = avg->cav[1] + ic * (avg->lav - avg->cav[1]);
  I_a = I_l + ia * (I_g - I_l);
  output[1] /= (output[1] + powf(f * I_a, m));
  I_l = output[2] + ic * (L - output[2]);
  I_g = avg->cav[2] + ic * (avg->lav - avg->cav[2]);
  I_a = I_l + ia * (I_g - I_l);
  output[2] /= (output[2] + powf(f * I_a, m));
}

void TonemapOperation::deinitExecution()
{
  this->m_imageReader = NULL;
  if (this->m_cachedInstance) {
    delete this->m_cachedInstance;
  }
  NodeOperation::deinitMutex();
}

bool TonemapOperation::determineDependingAreaOfInterest(rcti * /*input*/,
                                                        ReadBufferOperation *readOperation,
                                                        rcti *output)
{
  rcti imageInput;

  NodeOperation *operation = getInputOperation(0);
  imageInput.xmax = operation->getWidth();
  imageInput.xmin = 0;
  imageInput.ymax = operation->getHeight();
  imageInput.ymin = 0;
  if (operation->determineDependingAreaOfInterest(&imageInput, readOperation, output)) {
    return true;
  }
  return false;
}

void *TonemapOperation::initializeTileData(rcti *rect)
{
  lockMutex();
  if (this->m_cachedInstance == NULL) {
    MemoryBuffer *tile = (MemoryBuffer *)this->m_imageReader->initializeTileData(rect);
    AvgLogLum *data = new AvgLogLum();

    float *buffer = tile->getBuffer();

    float lsum = 0.0f;
    int p = tile->getWidth() * tile->getHeight();
    float *bc = buffer;
    float avl, maxl = -1e10f, minl = 1e10f;
    const float sc = 1.0f / p;
    float Lav = 0.0f;
    float cav[4] = {0.0f, 0.0f, 0.0f, 0.0f};
    while (p--) {
      float L = IMB_colormanagement_get_luminance(bc);
      Lav += L;
      add_v3_v3(cav, bc);
      lsum += logf(MAX2(L, 0.0f) + 1e-5f);
      maxl = (L > maxl) ? L : maxl;
      minl = (L < minl) ? L : minl;
      bc += 4;
    }
    data->lav = Lav * sc;
    mul_v3_v3fl(data->cav, cav, sc);
    maxl = log((double)maxl + 1e-5);
    minl = log((double)minl + 1e-5);
    avl = lsum * sc;
    data->auto_key = (maxl > minl) ? ((maxl - avl) / (maxl - minl)) : 1.0f;
    float al = exp((double)avl);
    data->al = (al == 0.0f) ? 0.0f : (this->m_data->key / al);
    data->igm = (this->m_data->gamma == 0.0f) ? 1 : (1.0f / this->m_data->gamma);
    this->m_cachedInstance = data;
  }
  unlockMutex();
  return this->m_cachedInstance;
}

void TonemapOperation::deinitializeTileData(rcti * /*rect*/, void * /*data*/)
{
  /* pass */
}
